The present invention relates to a numbering and imprinting machine which prints a number on a sheet.
A numbering and imprinting machine of this type includes a feed unit, printing unit, and delivery unit, as disclosed in Japanese Patent Laid-Open No. 2000-301688. The feed unit feeds a sheet. The printing unit includes a stamp cylinder and number cylinder arranged around an impression cylinder which holds and conveys the sheet fed from the supply unit. The delivery unit delivers the sheet having the stamp and number printed on it by the stamp cylinder and number cylinder, respectively.
In the conventional numbering and imprinting machine as described above, a top sheet for supporting the sheet is mounted on the circumferential surface of the impression cylinder, so it is necessary to perform an impression cylinder maintenance operation including an operation of cleaning or replacing the top sheet.
The conventional printing machine as described above is provided with a stamp cylinder and number cylinder arranged around the impression cylinder, and an ink supply device including a plurality of rollers in one-to-one correspondence with the stamp cylinder and number cylinder. For this reason, it is difficult for the operator (maintenance personnel) to access the impression cylinder, so he or she must enter the gap in one of a pair of frames of the printing unit in the maintenance operation of the impression cylinder.
In this case, after the operator accesses one end of the impression cylinder, he or she must move to the opposite printing machine frame to access the opposite side of the impression cylinder. Alternatively, two operators must perform each maintenance operation individually for one end and the other end of the impression cylinder, so the workability of the maintenance operation is poor.